Isolator switch for connecting two conductors



April 20, 1965 H. FoRwALD 3,179,760

/Mg/m,

United States Patent 3,179,760 ISOLATOR SWITCH FOR CGNNECTING TWO CONDUCTGRS Haakon Forwald, Ludvika, Sweden, assignor to Allmnna Svenska Elektriska Aktiebolaget, Vasteras, Sweden, a Swedish corporation Filed Feb. 4, 1963, Ser. No. 256,056 Claims priority, application Sweden, Feb. 9, 1962, 1 ,418/ 62 6 Claims. (Cl. 200-48) The present invention relates to a high tension isolator switch with a collapsible isolator arm containing a switch blade arranged to connect electrically two stationary contacts or conduits in order to close a high tension circuit. The invention is characterised in that the switch blade at one of its ends is pivotally journalled in one end of an insulator which at the other end is pivotally journalled in a preferably grounded stand arranged at full insulating distance from the stationary contacts. The isolator arm is provided with a link control system which, when the insulator during a disconnecting operation is swung to one side, causes the switch blade to fold against the insulator to such a position that all parts of the isolator arm in fully disconnected position are at full insulating distance from both the stationary contacts.

The isolator is especially suitable for connection of bus bar systems which cross each other at an angle of about 90. The arrangement according to the invention makes the whole isolator accessible in disconnected position without its being necessary to make any of the bus bar systems dead.

According to a specially suitable embodiment the switch blade is journalled at its lower end in the upper end of one of two substantially parallel insulators, which are spaced apart and are pivotally journalled in the stand at different heights. These insulators are pivotally joined at their upper ends, at points situated at equal distances from the respective lower journalling points of the insulators with an element, which by means of a link at a point situated on the switch blade near its journalling point is pivotally joined with this blade.

In the event that two crossing conduits are to be joined by the isolator switch blade, this is suitably provided at both ends with a grip contact. ,j

The element arranged in the toggle joint of the isolator arm is moved parallel to itself during opening or closing of the isolator. Therefore one of the above-mentioned grip contacts is suitably arranged on said element. Each grip claw of this grip contact is provided on the inside with a roller, theaxle of which is arranged in the longitudinal direction of the grip claw. The upper grip contact is influenced by a rod arranged inside the switch blade, which at the end of a closing operation is arranged to be displaced in relation to the switch blade and thereby to cause the grip contact to clamp onto the stationary contact or conduit.

The invention may best be understood with reference to the accompanying ligure which shows an embodiment of the invention.

In the figure the isolator switch blade is indicated by 1. In the Vparallel system which comprises the lower part of the isolator arm, the large insulator is indicated by 2 and the isolator belonging to the link control system by 2. The T-shaped element pivotally journalled at three points is indicated by 3, and the link between the element 3 and the switch blade 1 by 4. 5-9 indicate journalled junctions or bearings. The operating arm of the isolator is indicated by and is worked by a piston (not shown) in a cylinder 11. To facilitate the operating of the isolator arm the insulator 2 is suitably provided with counterweight 12. The isolator arm is arranged on a suitably grounded stand 13.

ICE

The insulators 2. and 2 of the isolator are joined at points Sand 6 in a parallel system, i.e. form a parallelogram with the arms 2 and 2 and lines drawn through the points 5 and 6 as sides. Since the points 5 are fixed points in the system, a line drawn between the points S will always have a constant inclination to the horizontal plane. From this it follows that aline through the points 6 must also have a constant inclination to the horizontal plane when said lines are parallel, since the arms 2 and 2' are of equal length and parallel. Hence it is evident that the element 3 alwayshas constant inclination towards the horizontal plane and is thus especially suitable to x a grip contact 14 on. 15 indicates the upper grip contact, the grip claws of which are influenced by a cone ring 16 which in its turn may be displaced axially by means of the tube-shaped rod 17 inside the isolator switch blade 1. At the upper end of the isolator switch blade 1 a slot 18 is arranged. Through the slot runs a pin 19 which firmly joins the cone ring 16 and the rod 17. The rod 17 is influenced below by a stop bolt 22 xed on the arm 2.

The grip claws of the grip contact 14 are provided on the inside with cylindrical rollers, the upper ends of which are tapered, with their longitudinal axis arranged vertically. The isolator is intended to connect together one phase of two conduit Systems 2li and 21 crossing each other at different heights.

Driving closing movement of the isolator arm this is straightened out and the switch blade 1 is conveyed towards the :switching-in position between the conduits. Thereby the grip Contact 14 is moved parallel to itself and near the switching-in position will move over a phase conductor 20 to a closed position. The upper grip contact closes over the phase conductor 2l.. Near the closed position the rod 17 is forced upwards by the stop bolt 22. The pin 19 moves upwards in the slot 18 and thereby takes the cone ring 16 upwards, upon which the grip claws are pressed against the phase conductor 21. In completely closed position the rod 17 sinks back somewhat and the pin 19 will thus take up an approximately central position in the slot 18. This is due to the fact that the journalling point 9 in the completely closed position of the isolator arm has been carried beyond the straight line which is then formed by the isolator switch blade 1 and the insulator 2.

In an opening operation the grip contact 15, on the basis of the last-mentioned conditions, is conveyed rst slightly upwards while on the other hand the cone ring 16 and the Irod 17 hardly change their levels at all. The grip claws of the upwards moving sliding contact 15 thereby release their hold `on the conductor 21. The insulator 2 swung to the side and simultaneously the isolator switch blade 1 is folded towards the insulator 2. The whole isolator arm is moved to completely disengaged position, in which, as is evident from the drawing, the isolator arm in all parts is at full insulating distance from the phase conductor 20.

It may of course be feasible to make the isolator switch blade 1 double, for which a switch blade is arranged on each side of the phase conductor Ztl and is supplied at the top with a sliding contact.

I claim:

l. In an isolator switch for connecting and disconnecting two stationary conductors located at dilterent heights, a stand, and a movable assembly comprising an elongated insulator member pivotally journalled at its lower end in said stand, a switch blade pivotally journalled at its lower end in the upper end of the insulator member, means operatively connected to said insulator member for moving it with respect to the stand between a substantially vertical position and a substantially horizontal position, means operatively connected to the insulator member and the switch blade, responsive to such movement of the insulaair/aree 3 tor member, to move the switch blade between a substantially Vertical position extending upwardly from the upper end of the insulator member to a substantially horizontal position generally parallel to the insulator member, a first Contact carried by the switch blade at the upper end thereof, and a second contact carried by said assembly in insulated relation with respect to said stand and electrically connected with the irst contact positioned at a level substantially below the level of said lirst contact when said switch is in a `closed position, said contacts being respectively engageable with such conductors when the insulator member is in vertical position, all of the parts when the insulator member is moved to horizontal position lying at full isolating distance vtrom the stationary conducto-rs.

2. ln a device as claimed in claim l, at least one of said contacts comprising a grip Contact.

3. ln a device as claimed in claim 2, a rod inside said switch blade operatively connected to said grip Contact, and means for displacing said rod in relation to said switch blade at the end ot a closing operation to operate the movable grip contact.

4. In an isolator switch for connecting and disconnecting two stationary conductors located at dilerent heights, a stand, and a movable assembly comprising two parallel elongated insulator members journalled in said stand about rst points of different height, a switch blade pivotally journalled at its lower end in the upper end of one of the insulator members, a connecting element pivoted to second points at the upper ends of both insulator members, the line joining the first points being parallel to and of equal length to the line joining the second points, a link pivoted to the connecting element and to the lower part of the switch blade, means operatively connected to said insulator members for moving them with respect to the stand between a substantially vertical position and a substantially horizontal position, said connecting member and link, during such movement'of the insulator members, producing movement of the switch blade between a substantially vertical position extending upwardly from the upper end of the insulator members to a substantially horizontal position generally parallel to the insulator members, a iirst contact carried by the switchblade at the upper end thereof, and a second Contact carried by said assembly in insulated relation with respect to said stand and electrically connected with the first contact positioned at a level substantially below the level oi' said first Contact when said switch is in a closed position, said contacts being respectively engageable with such conductors when the insulator members are in vertical position, all or" the parts when the insulator members are-moved to horizontal position lying at full isolating distance from the stationary conductors. Y

ln a device as claimed in claim 4, said second contact being mounted on said connecting member.

6. ln a device as claimed in claim 5, said connecting member including a vertically extending part carrying said second contact, whereby said second contact remains in vertical position during movements of the assembly.

liererences Cited by the Examiner FORElGN PATENTS 560,703 9/57 Belgium.

BERNARD A. GILHEAVY, Pnmry,xf'zlm'ner.v ROBERT K. SCHAEFER, Examiner. 

1. IN AN ISOLATOR SWITCH FOR CONNECTING AND DISCONNECTING TWO STATIONARY CONDUCTORS LOCATED AT DIFFERENT HEIGHTS, A STAND, AND A MOVABLE ASSEMBLY COMPRISING AN ELONGATED INSULATOR MEMBER PIVOTALLY JOURNALLED AT ITS LOWER END IN SAID STAND, A SWITCH BLADE PIVOTALLY JOURNALLED AT ITS LOWER END IN THE UPPER END OF THE INSULATOR MEMBER, MEANS OPERATIVELY CONNECTED TO SAID INSULATOR MEMBER FOR MOVING IT WITH RESPECT TO THE STAND BETWEEN A SUBSTANTIALLY VERTICAL POSITION AND A SUBSTANTIALLY HORIZONTAL POSITION, MEANS OPERATIVELY CONNECTED TO THE INSULATOR MEMBER AND THE SWITCH BLADE, RESPONSIVE TO SUCH MOVEMENT OF THE INSULATOR MEMBER, TO MOVE THE SWITCH BLADE BETWEEN A SUBSTANTIALLY VERTICAL POSITION EXTENDING UPWARDLY FROM THE UPPER END OF THE INSULATOR MEMBER TO A SUBSTANTIALLY HORIZONTAL POSITION GENERALLY PARALLEL TO THE INSULATOR MEMBER, A FIRST 